Help! 2004 Dodge Durango radio wiring

Does any one know of a wiring diagram for a 2004 SLT Dodge Durango? I was checking the voltages on the factory connector and there is 2-12v constants, 2-grounds and no 12v acc. I don't know what is going on. Everyone I see online doen't match as far as colors. Can anyone shed some light on this? Also, how can you tell if it is an infinity system without looking at the speakers? Thanks,